Sudden death in patients with coronary artery disease is considered to be due to disturbances in heart rhythm (e.g., ventricular fibrillation or cardiac asystole). Indirect evidence indicates that these arrhythmias occur because of an interaction of altered autonomic neural activity with ischemic myocardial tissue. I intend to study this interaction during experimentally-induced myocardial infarction by recording from afferent and efferent cardiac nerves and correlating alterations in nerve activity with alterations in cardiac electrical activity. In addition to these correlation studies, I will examine cause-effect relationships between nerve activity and cardiac rhythm changes by observing the influence of selective denervation of afferent nerves on efferent nerve activity and cardiac electrical activity. The proposed research, by defining more clearly the relationship between the nervous system and the heart, should lead to a better understanding of the normal and abnormal events that occur in that relationship. This knowledge should lead to new and better prophylactic and therapeutic measures for the management of cardiac disorders. BIBLIOGRAPHIC REFERENCES: Coor, P.B. and Gillis, R.A.: Effect of autonomic neural influences on the cardiovascular changes induced by coronary occlusion. Amer. Heart J. 89: 766-774, 1975. (Article). Gillis, R.A., Quest, J.A. Thibodeaux, H., Clancy, M.M. and Evans, D.E.: Neural mechanisms involved in acetylstrophantihidin-induced bradycardia. J. Pharmacol. Exp. Ther. 193: 336-345, 1975. (Article)